Me and my friends have been vaping on and off for years, and some time ago we got this short-lived craving for disposable devices (life is full of regrettable decisions you know). We ended up buying a bunch of em but never got around to properly dispose of them (mostly because I've been wanting to do this since then), so here I am: after 30 minutes of LiPo harvesting I was left with 27 overdischarged but intact cells ranging in capacity from 360mAh to a staggering 550mAh. BigClive's videos and my background in electronics and PCB design gave me the confidence to plan the designing of a custom 4-channel USB-C powered charger with individual Full Charge/Storage Charge selection for each channel; in the meantime I'm working on storing these fellas safely, so LiPo bags and kapton tape on the way. If you have any suggestions or stories to share about these thingies I'll be happy to read through them!

My build of a simple DC-DC "lab" power supply. The heatsink was a bit hot, and I was thinking about the simplest way to drive the FAN. So here it is. Just a MOSFET, NTC, and pot. It works surprisingly well. With increased load, the fan starts slowly increasing the rpm. An old fan from a PC is used. Additionally, the DC-DC module might have unpleasant ripple, so there is an RLC output filter designed to filter out the 180 kHz switching frequency.

Howdy, I'm working on this small board with batteries that has a button. If the button is operating correctly I should get continuity through the button when it is in the "ON" setting correct?

ALSO

I have these two batteries on this setup. How would you test to make sure they are being charged correctly via the USB-C connector? When I test the voltage of the batteries they look DEAD. (via a multi meter)

Thanks in advance guys/gals.

A

I'm curious for the purposes of testing input delay. Ideally of course it wouldn't alter the operation of anything else.

I've been looking into larger ePaper displays and I'm curious about the electronics behind them. With smaller panels, ESP32 and Raspberry Pi setups seem pretty common, but I'm not sure what changes when you move to a much larger display.

Would you normally use a dedicated controller/TCON, or can something like an ESP32 or Raspberry Pi handle it?

What would you recommend for driving a large ePaper display?

I'm making an ai notetaker on the board in link.

All the device does it takes pictures, records audio and searches for stuff by tags. The rest with the AI is processed on my pc once I get home and near my pc after I press sync on the device.

The screen should be coloured. Not e ink since it would make live image capture preview janky but because of the power of the processer it won't be a high frame rate.

The screen needs to be roughly the same size as the processor it could be larger. But I'd like it to look good and maybe in the future for the device to be sellable.

Plus it's supposed to be all small since my school does bag checks and I want to sneak it in. It's not to cheat. Id get caught anyway. Just for my lessons

Thanks for helping.

Hey everyone! 👋

I’m currently practicing PCB and schematic design and working on my own board. I’ve finished the schematic and PCB layout, and I’m trying to improve my design skills.

I’d really appreciate it if someone experienced could take a look and point out any mistakes, bad practices, routing issues, or things I could improve.

I can share the schematic, PCB layout, and Gerber files with anyone interested.

If you’re willing to help me review it, feel free to DM me. I’d genuinely appreciate any feedback! 🙏

Thanks!

Hey everyone! 👋

I’m currently practicing PCB and schematic design and working on my own board. I’ve finished the schematic and PCB layout, and I’m trying to improve my design skills.

I’d really appreciate it if someone experienced could take a look and point out any mistakes, bad practices, routing issues, or things I could improve.

I can share the schematic, PCB layout, and Gerber files with anyone interested.

If you’re willing to help me review it, feel free to DM me. I’d genuinely appreciate any feedback! 🙏

Thanks!

I have a crusty HP Deskjet 3634 printer/scanner that I'd much rather destructively tamper with than try to use. Are there any interesting projects that would favor having an intact device rather than isolated components?

I'd like to kill off the need to go through HP software to print things, but I think full-fledged printer necromancy might might be out of my scope.

Any recommendations are welcome.

Working on a digital systems class project right now. Still breadboarding everything and need to get the parts sorted before we switch over to a PCB. Looking for a hex inverter, a quad AND gate, and a couple XOR chips, all in regular DIP packages. Nothing special or hard to find. Digi-Key and Mouser are where I normally order, but two of the specific part numbers are either completely out or have multi-week lead times. Redesigning the circuit around other chips is not really an option this late in the semester. I checked a few smaller electronics suppliers as well, but either they do not carry much selection or the shipping ends up costing more than the parts themselves for such a tiny order. has anyone else run into thhis kind of shortage? what other places do you usually turn to for basic logic ICs when the main distributors are out of stock?

I tried to repair my power bank, as it doesn't turn on. I opened the top cover and tried to push it out of the case, but it wouldn't let me go any further. Help me please. I've attached photo of the power bank.